1. Field of the Invention
The present invention relates to an improvement of a check valve disposed in a pressure circuit wherein a fluid serves as a control medium.
2. Description of Relevant Art
Check valves disposed in a pressure circuit are generally of a construction which includes a valve body seated on biasing means such as a spring, positioned in an oil path of a valve case for the purpose of closing the same path, and adapted to permit flow only in a predetermined direction of fluid having a pressure exceeding a preset value.
Check valves of this sort are adapted to open and close at a pressure level preset for their operation as a limit, but in the vicinity of such preset level of pressure the opening and closing motions of the valve are not effected instantaneously. The result is that changes in fluid pressure sometimes cause the valve body to vibrate and the valve exhibits the so-called chattering phenomenon.
In view of the above-mentioned problem associated with check valves of this sort, the present inventors have continued the present invention in order to overcome such problem effectively.